One simple reason is happiness. The peace and happiness of parents, for example, depend upon their children having affection and compassion towards them.  And the children's peace and happiness depend upon their parents' affection and compassion. The same is true for couples, partners, teacher and students etc: each member's peace, happiness and success depend upon the compassion and kindness of the other person. And on a larger scale, the relationship between the leader of a country and its population.

One has to know how to develop such qualities. This is the first reason for doing retreat - to develop the basic human qualities of affection and loving kindness. The second reason is that it gives us the time for putting into practice the teachings we have received.  The third reason relates to the busyness of our ordinary life:  we are generally so caught up in hallucinations, sense enjoyments and our various obligations to others that retreat time is the only time we have to relax. In a retreat situation, you are forced to come to face with yourself, to see yourself in depth, to meet yourself.  

Reciting powerful mantras and names of holy beings even once can purify tremendous amounts of negativity.  Meditating on the path to enlightenment helps rid us of immediate dangers, such as rebirth in the lower realms if death is imminent. At the same time, such meditational practice can purify the causes of this life's problems from difficult relationships, through unmanageable diseases such as cancer and AIDS up to dangers of untimely death.  Because one creates a great deal of merit through these practices, they become the cause of success and harmony in this life, bringing good fortune in business, wealth, good health and long life. 

 For all the above reasons, therefore, retreat gives us more hope, strength and encouragement for this life.  In conclusion, retreat is important because it involves retreating from ignorance, from the dissatisfied mind of attachment and from the self-cherishing thought.  This are the fundamental forces from which one must retreat.  Transforming the mind into virtue, freeing oneself from suffering and its causes: these are the essential meaning of Dharma practice.